Estimation of Sq variation by means of multiresolution and principal component analyses

A wavelet based method of deconvoluting the solar quiet variation from the low and mid-latitude H-component records is proposed. This approach uses data from multiple stations, involves wavelet analysis techniques, and functional principal component analysis. The procedure removes the signature of an enhanced ring current by comparing the scores at different stations. The resulting daily variation is non-constant, and its day-to-day variability is quantified by principal component scores. The method is fully algorithmic and is implemented in the open source statistical software R package WAMI. It can be computed in real time over the moving window as soon as new magnetogram records become available.